We have two Acer desktops here that came with the Windows 7 Upgrade kit.
The DVD is the full Windows 7 installation DVD with nothing added. The other disk is a drivers
and programs disk for you to choose from. You shouldn't need any drivers since the Windows 7 DVD is driver
-complete, with newer arriving quickly via optional Windows Updates. Any drivers then missing in Device Manager can be found on the Acer Support Downloads webpage for your model.
So in the scenario you pose with a virus attack, you'd want to back up your data to quarantine on DVD, external or flash stick, where it can be thoroughly scanned by AV and Malwarebytes. http://www.malwarebytes.org/
Next wipe your HD before reinstall to overwrite any infected or corrupt code. This is because deleting or formatting doesn't erase anything since you can't actually erase data off of a Hard Drive, only overwrite it with all zeroes which is what wiping does. Boot the Windows 7 DVD, press Shift+F10 at first screen to open a Command line and type the Diskpart Commands given in this tutorial to wipe the HD: SSD / HDD : Optimize for Windows Reinstallation How to boot from CD/DVD
Next boot the Windows 7 DVD, select Custom Install, then use Drive Options (Advanced) to create and format your install partition before installing Windows 7. The steps are all shown here: Clean Install Windows 7
Some other tips to get a perfect install:
Install updates and then programs slowly over time to gauge performance after each. Don't let any programs write themselves into your Startup list as they become freeloaders on RAM/CPU and can spy on you. I only allow AV and gadgets. Startup Programs - Change
Use a lightweight free Anti-Virus like MS Security Essentials which works perfectly with Windows 7 Firewall. http://www.microsoft.com/security_essentials/
When it is finished, clean and order the HD perfectly using state-of-the-art free CCleaner then Auslogics Disk and Registry defraggers monthly. CCleaner - Free software downloads and software reviews - CNET Download.com Auslogics Disk Defrag - Reviews and free Auslogics Disk Defrag downloads at Download.com Auslogics Registry Defrag - Free software downloads and software reviews - CNET Download.com
Then save a Windows 7 Backup image externally so you never have to reinstall again, just reimage the HD or replacement using DVD. Backup Complete Computer - Create an Image Backup System Image Recovery
Read over these steps then post back as many questions as you need answered.